Toothbrush having main bristles and having transversely and longitudinally adjustable interdental bristles
The invention relates to a toothbrush having a grip member and having a cleaning member, which is connected to the grip member and which extends substantially parallel to a cleaning-member longitudinal direction, and having drive means, which are partly accommodated in the grip member and partly in the cleaning member and which include a drivable first drive element and a drivable second drive element in the cleaning member in the area of that end of the cleaning member which is remote from the grip member, and having a drivable bristle holder which holds a plurality of main bristles and which is coupled to the first drive element with the aid of a first coupling element, and having a drivable interdental bristle holder, which holds a plurality of interdental bristles which extend substantially parallel to a longitudinal bristle direction, which is oriented transversely to the cleaning-member longitudinal direction, and which is coupled to the second drive element with the aid of a second coupling element.
The invention further relates to a cleaning member which extends substantially parallel to a cleaning-member longitudinal direction, and which has drive means, which include a drivable first drive element and a drivable second drive element in the area of one. end of the cleaning member, and which has a drivable bristle holder, which holds a plurality of main bristles and which is coupled to the first drive element with the aid of a first coupling element, and which has a drivable interdental bristle holder, which holds a plurality of interdental bristles which extend substantially parallel to a longitudinal bristle direction, which is oriented transversely to the cleaning-member longitudinal direction, and which is coupled to the second drive element with the aid of a second coupling element.
A toothbrush and a cleaning member as defined above are known from the patent document U.S. Pat. No. 5,836,030 A. Such a toothbrush has been put on the market by the Applicant and has proved to be comparatively successful. In order to obtain a satisfactory overall cleaning result with such a toothbrush, as well as with any other toothbrush, it is very important to achieve a good cleaning action in the interdental areas. In this respect it has proved to be disadvantageous with the known toothbrush and with the known cleaning member that the second coupling element and the second drive element are of a stiff construction and consequently form a more or less rigid unit.
It is an object of the invention to provide an improved cleaning action in a simple manner and by simple means both at the main dental areas and in the interdental areas and thus achieve an improved overall cleaning result with a toothbrush and with a cleaning member as defined above.
According to the invention, in order to achieve the afore-mentioned object, t a toothbrush of the type defined above is provided in which of the second coupling element and the second drive element, at least the second coupling element is at least partly elastically deformable substantially parallel to the longitudinal bristle direction of the interdental bristles.
According to the invention, in order to achieve the afore-mentioned object, a cleaning member is provided in a toothbrush of the type defined above in which of the second coupling element and the second drive element, at least the second coupling element is at least partly elastically deformable substantially parallel to the longitudinal bristle direction of the interdental bristles.
By providing the characteristic feature in accordance with the invention an improved cleaning action is achieved at the main tooth areas with a toothbrush in accordance with the invention and with a cleaning member in accordance with the invention, because at these areas the mostly longer interdental bristles recede and, as a result of this, both the interdental bristles and the main bristles, which are disposed directly adjacent the interdental bristles, are capable of providing an intensive cleaning contribution. In addition, an improved cleaning action in the interdental areas is achieved because the interdental bristles perform not only a movement substantially parallel to the interdental areas but, in addition, can also perform a movement perpendicularly to the interdental areas and perpendicularly to the main tooth areas. In this respect it is very essential that the afore-mentioned additional movement of the interdental bristles is independent of the relative position of the interdental bristle holder with respect to the bristle holder, as a result of which the interdental bristle holder and, consequently, the interdental bristles can perform a movement which is oriented substantially parallel to the longitudinal bristle-direction of the interdental bristles. This is true also in the case when the interdental bristle holder is pivotable owing to the elastic deformability of at least the second coupling element and, when applicable, also of the second drive element, because in this case a comparatively large pivoting radius, i.e. a comparatively long lever arm, which is independent of the relative position with respect to the bristle holder, can be obtained for the interdental bristle holder.
It is to be noted that from the patent document WO 97/07707 A1 a toothbrush is known in which a bristle holder and an interdental bristle holder have been provided but in which neither the bristle holder nor the interdental bristle holder is drivable with the aid of drive elements of drive means and in which the interdental bristle holder is connected directly to the bristle holder. Although in this case the connection between the bristle holder and the interdental bristle holder is elastically deformable, the interdental bristle holder can perform only a pivotal movement defined by the elastically deformable connection between the bristle holder and the interdental bristle holder, i.e. a pivotal movement which is dependent on the relative position of the interdental bristle holder with respect to the bristle holder, in other words a pivotal movement having only a comparatively small pivoting radius, i.e. a comparatively short lever arm, which is less favorable for the cleaning of the interdental areas because the interdental bristles perform not only a movement substantially parallel to the longitudinal brush-direction of the interdental bristles but, with their free ends, also a movement oriented transversely to the longitudinal brush-direction of the interdental bristles and transversely to the interdental areas, which is less favorable for a deep cleaning of the interdental areas.
Both the second coupling element and the second drive element of a toothbrush and a cleaning member in accordance with the invention can be of an elastically deformable construction, which is particularly favorable in order to obtain a lever arm of maximal length. However, it has proved to be very advantageous when, in addition, a toothbrush and a cleaning member are provided in accordance with the invention wherein the second coupling element is formed by a metal blade spring configuration having a first end portion, an intermediate portion and a second end portion, the interdental bristle holder is connected to the first end portion, and the second drive element is connected to the second end portion. This has proved to be particularly advantageous in view of a construction which is as simple and reliable as possible.
Moreover, it has proved to be very advantageous when, in addition, the characteristic features are provided in a toothbrush wherein the second drive element consists of a plastic, and the connection between the second end portion and the second drive element is formed by an injection-molded connection and/or wherein the interdental bristle holder consists of a plastic, and the connection between the first end portion and the interdental bristle holder is formed by an injection-molded connection. This has proved to be very favorable in view of a construction which is as simple and reliable as possible.
However, it has also proved to be very advantageous when, in addition, the characteristic features are provided in a toothbrush wherein the second drive element and the second coupling element as well as the interdental bristle holder consist of an integral part made of a comparatively hard plastic, and the second coupling element is constructed as a bending element, and at least the second coupling element is embedded in a cover which consists of a comparatively soft plastic. In especially preferred embodiments, the comparatively hard plastic is polyoxymethylene, and the comparatively soft plastic is a thermoplastic elastomer. This enables a solution that is particularly favorable with regard to the pivotal movement of the interdental bristle holder to be realized because the flexural element guarantees stability and the soft component surrounding the flexural element damps the deflection movements in an advantageous manner.
The above-mentioned as well as further aspects of the invention will become apparent from the two embodiments described hereinafter by way of example and will be elucidated with reference to these two examples.